This is very hard, Brahms 2nd is such a versatile and so full of room for interpretation for both pianist and orchestra.
these are the ones i really like
7 different recording of Richter (Mutti, Leinsodorf, Mrvanisky, Kondrashin, Munch, Georgescu, Maazel)
Gilels Reiner and Jochum
Fleisher's
Zimerman
and the new Freire
the young Rubinstein's recording is actually very brilliant
Also the Horowitz's, the ones with Toscanini, it's just insanity with fierce
Koji and Katsaris's recordings are worthy of mentioning among all the other masters.
But overall it has to be the re-mastered Gilels with Reiner (can be found in the great conductor series, Reiner's 2 CD set, which has all kind of goodies in too)
Because it's the most all around outstanding recordings.
But all the others ones have their own greatness in different sections.
sidestory, if Kapell didn't die from the airplane crash, he would have record this very concerto the year after.